Astra 6731i - Local SIP port

[info@fusionit.eu]

I have a couple of Astra phones running SIP firmware, connecting to FusionPBX(freeswitch)

No matter what I do the phones show registered on my server with random SIP ports, I'm using tcp,

Under network settings I've set "nat sip port" to 1026 - see attached
under global sip settings, I've set local sip port to 1026 - see attached

However every time the phone connects it's getting a different SIP port registering on my server, outgoing calls are fine, incoming are not unless I then manually set the sip ports to reflect the random port chosen on the server....problem is when I reboot the phones a new random port is assigned server side and then incoming calls cease to work again.

I've already tried UDP and cannot get them to register unless they use port 5060 which then doesn't even allow incoming or outgoing calls. All other phone types are working perfectly with either tcp or udp...it's just these two Astra's that won't play nice...

Any help much apprecaited!

[dilkie]

you should be using a persistent connection (tls or tcp, tls preferable) and not using local sip port (you're behind nat, so pointless).

for udp, you need to configure sets to use OPTIONS or some other means to keep the nat bindings active.

and, of course, you need a server that understands how to deal with natted sip devices (like what MBG does). That's the job of the SBC, not usually the call server itself.